oxy sensor fail and EMS light on

[nobby]

hi

have an oxygen sensor fail, so was wondering is it best not to drive the car until this issue has been resolved?

EMS light now on dash ... is car rounning in any type of 'safe mode'?

certainly does not feel any less different than normal

have checked other forum posts so looking into an ebay special to purchase etc

HUK is staying true to form on its pricing ... close to £200 for one :(

any thoughts let me know

ta

[Kaz-kzukNA1]

Looks like you have already read the error code.

If the O2 sensor failure was not caused by other issues such as short circuit created by the damaged wire and presuming that you don't have any other engine issues, then you are very likely to be fine for the normal driving conditions.
As you should know which sensor has failed by reading the code, I would just disconnect the connector for that sensor to minimise any un-known factor.

When the O2 sensor fails, the ECU fuel timer calculation will go into Open loop mode and use the base map with default value for the co-efficient so you may feel something different or nothing.

As it is in Open loop mode, you may see your fuel mileage getting worce.

The CAT won’t work efficiently under Open loop mode because it needs oxygen to resolve itself. This is one of the reason why you see the SIN wave like Rich – Lean – Rich output from the O2 sensor under Closed loop control for fuel efficiency as well as for the CAT.
I don’t have enough experience and knowledge to comment on the long term effect on the CAT if driven in Open loop mode for many years/miles.

You can get the cheap sensor from ebay but I tend to prefer the ones from Denso or NTK/NGK.

I normally buy them from US. http://sparkplugs.com/
(http://sparkplugs.com/)If I remember correctly, the delivery charge was the same between sending just one or two sensors so you may want to consider getting multiple sensors at the same time depending on the spec of your NSX.

Please note that Acura introduced OBD-II spec for US NSX from 95 onwards so you need to be very careful buying the parts around the exhaust area based on the ‘Year model’. The CAT area design is also different.
For example, the cable length of the O2 sensor for a certain US model could be different from the one on the same year UK model.

If my memory is correct, I know your NSX spec and if it is the same one as before, I have two new spare NTK/NGK O2 sensors. One of them belongs another owner.

Hope you will be able to sort out the issue very soon.

Kaz

[nobby]

Hi Kaz

thanks for the info ... tbh the fault has happened due to changing the manifolds ... on the tester the sensor is 'open' so zero reading on the meter ... and the car threw the light on ... we have done the ecu diagnostic - no 42 i think and it points to failed oxy sesnor.

tbh i dont plan to drive the car too much until issue is FULLY resolved ... but i need to take the car out for a proper run to test the car ... as i only picked the car up late last night and have not got a proper drive due to wanting to get home etc. that way when i go back to getting sensor replaced i can say to mechanic that this and that is happening (if anything)

I would be grateful if you can send me a PM regarding the price for one of the sensors you have if its available for sale ... save me going down other avenues. I have your number so i can text you this request also. My mechanic has other sensors in stock as he is an Evo Specialist and has Denso ones etc, but he wanted to confirm fitting etc. He would be able to splice wires etc as long as sensor end is correct; but i want to confirm on the forums before perhaps going down this route

Yeah you should have my car details from the abs upgrade information etc.

many thanks as always! :)

andrew